[river_fish]

Dear community,

I am computing a 3D-simulation of open-channel flow using InterFoam. I want to compare my results (velocity) with a previous 2D simulation flow field, which means I need to compute the average velocity along z-direction for the cells which contain water. What I have done so far:

1. Threshold filter for phase alpha to remove cells with air
2. Interpolate velocity on regular grid

You can see how the result looks in paraview below.

Now it seems it should be easy to get the vertical average value but I haven't found the right operation yet. Does anybody know the answer in Paraview or can help me to convert the vtm file to numpy array (which I can handle)?

Thanks a lot!